18 Feb 2004 I n t e g r i t y - S e r v i c e - E x c e l l e n c e Estimating Influenza Vaccine Effectiveness in the DoD Col James Neville, MD, MPH Deputy Director Sustaining Readiness through Healthy Communities

18 Feb 2004 I n t e g r i t y - S e r v i c e - E x c e l l e n c e Topics to be Covered Existing surveillance programs (overview) Data available for evaluation of VE Navy VE estimate (recruit centers) Army VE estimate (Ft. Lee outbreak) AF VE estimate (phone survey, underway)

18 Feb 2004 I n t e g r i t y - S e r v i c e - E x c e l l e n c e Existing Surveillance Programs-AF AF Program (AFIOH) 27 sentinel sites Clinical and convenience sampling 1 O objective: isolates Collaborating Sites

18 Feb 2004 I n t e g r i t y - S e r v i c e - E x c e l l e n c e Existing Surveillance Programs-Navy AF Program (AFIOH) 27 sentinel sites Clinical and convenience sampling 1 O objective : isolates Navy Program (NHRC) Military Training Centers Convenience sampling Objective: ILI rates, isolates Lackland AFB Great Lakes Ft Jackson MCRD Parris Island Ft Leonard Wood MCRD San Diego Ft Bragg Cape May

18 Feb 2004 I n t e g r i t y - S e r v i c e - E x c e l l e n c e Existing Surveillance Programs-Army AF Program (AFIOH) 27 sentinel sites Clinical and convenience sampling 1 O objective: isolates Navy Program (NHRC) Military Training Centers Convenience sampling Objective: ILI rates, isolates Army Program MEDCENs, clinical virology labs Special studies - Army MEDCEN

18 Feb 2004 I n t e g r i t y - S e r v i c e - E x c e l l e n c e ILI Activity Data Sources

18 Feb 2004 I n t e g r i t y - S e r v i c e - E x c e l l e n c e ILI Activity Data Sources Local public health officer reports

18 Feb 2004 I n t e g r i t y - S e r v i c e - E x c e l l e n c e Data Sources (cont’d) Local public health officer reports Coded ambulatory visits –ESSENCE –“DNBI”

18 Feb 2004 I n t e g r i t y - S e r v i c e - E x c e l l e n c e Data Sources (cont’d) Local public health officer reports Coded ambulatory visits –ESSENCE –“DNBI” Laboratory results –Surges from a site –Unusual results

18 Feb 2004 I n t e g r i t y - S e r v i c e - E x c e l l e n c e Data Sources (cont’d) Cumulative AF Influenza Vaccination Local public health officer reports Coded ambulatory –ESSENCE –“DNBI” Laboratory results –Surges from a site –Unusual results Immunization data –Individual level

NHRC VE Data Existing data from surveillance program –Trainees at 4 training bases –December 2003 Influenza culture positives only Person-time analysis –Weeks at risk –Vaccinated vs. unvaccinated (2 wks post vax) Basic trainees are vaccinated upon arrival

NHRC data (cont’d)

VE calculation AR vax = 4 cases / person-wks – 7.37/100,000 person-wks AR unvax = 15 cases / person-wks –80.6/100,000 person-wks RR = 7.37 / 80.6 = VE = 1 – RR = 90.9%

18 Feb 2004 I n t e g r i t y - S e r v i c e - E x c e l l e n c e Ft Lee, Virginia US Army post - Quartermaster Training –3,200 trainees; courses of varying length; 12%/week turnover Influenza outbreak, 31 Oct-11 Nov 2003

18 Feb 2004 I n t e g r i t y - S e r v i c e - E x c e l l e n c e Ft. Lee ILI Epi Curve Mass Immunizations CHPPM/WRAIR EPICON

18 Feb 2004 I n t e g r i t y - S e r v i c e - E x c e l l e n c e Ft Lee, Virginia US Army post - Quartermaster Training –3,200 trainees; courses of varying length; 12%/week turnover Influenza outbreak, 31 Oct-11 Nov 2003 PH response: mass immunization, case isolation Vaccine Effectiveness Study Attempt –2 cohorts –“tight” and “loose” case definition –Limitations – temporality, highly immunized population, exhaustion of susceptibles, random mixing assumption

18 Feb 2004 I n t e g r i t y - S e r v i c e - E x c e l l e n c e VE Results “loose” case def.“tight” case def. Cohort A: arrival date 10 Nov 03 (n=267) 40.5% [-48%, 76%] (26 cases) 51.2% [-357%, 78.1%] (5 cases) Cohort B: arrival date 17&24 Nov 03 (n=463) 60.2% [-167%, 86.4%] (15 cases) 100%; no CI by method used (4 cases)

18 Feb 2004 I n t e g r i t y - S e r v i c e - E x c e l l e n c e AF IVE Evaluation: Plan A Identify exposed cohort (AF only, not Academy) –Index cases: influenza culture positive in AFIOH lab Contact sponsor for household health histories –Influenza vaccinations –Febrile respiratory illnesses within 2 wks of index case Calculate secondary attack rate –Compare vaccinated and unvaccinated IRB approved; telephone surveys began 2 Feb 2004 –results pending Annual routine study? # eligible = 114 Total # of family members=400 # specimens=2459 # positive = 859

18 Feb 2004 I n t e g r i t y - S e r v i c e - E x c e l l e n c e Identify site with ongoing transmission –Lab submissions, ESSENCE, other reports –Index cases: influenza culture positive in AFIOH lab Decision: Launch on-site investigation vs. telephone only –Surveillance data sources to assess extent of local outbreak Contact sponsor/parent directly for household health histories –Influenza vaccination history –Febrile respiratory illness within 2 wks of index case Validate data with medical records, vaccination registry, labs Use secondary attack rates to estimate VE Annual routine study? Pending IRB & AF approval AF IVE Evaluation: Plan B

18 Feb 2004 I n t e g r i t y - S e r v i c e - E x c e l l e n c e Summary NHRC: VE = 91% CHPPM: VE = % AF: VE = pending Many details...

18 Feb 2004 I n t e g r i t y - S e r v i c e - E x c e l l e n c e Questions Contact information: Col James Neville, MD, MPH Phone:

18 Feb 2004 I n t e g r i t y - S e r v i c e - E x c e l l e n c e Back-ups

18 Feb 2004 I n t e g r i t y - S e r v i c e - E x c e l l e n c e Specimen Results by Week of Training

18 Feb 2004 I n t e g r i t y - S e r v i c e - E x c e l l e n c e AF Lab Results

18 Feb 2004 I n t e g r i t y - S e r v i c e - E x c e l l e n c e AF Lab Results